How high should HPS grow lights be placed?
So, even when the grow light is hung low over the canopy, some light is going to go over the plants and hit the side wall of the grow tent. The optimum hanging height for a 600W HPS system is only 40cm or 16".
For a 400W and 600W lamps used in a 1.0m to 1.2m square tent, start off placing the lamp and reflector at about 18"-24" from the tops of your plants.
As an unofficial rule of thumb, many growers work on the basis that: You need 20-40 watts of power per square foot. Lower wattage LEDs of around 200 watts should sit between 12-20 inches from the top of the plant. Higher wattage LEDs of 1000 watts and above should sit between 36-46 inches from the top of the plant.
| Grow Light | Closest | Furthest |
|---|---|---|
| 150W | 8″ (20cm) | 12″ (30cm) |
| 250W | 10″ (25cm) | 14″ (35cm) |
| 400W | 12″ (30cm) | 19″ (48cm) |
| 600W | 14″ (35cm) | 25″ (64cm) |
| Grow Tent Size | Watt Needed | Number Of Plants |
|---|---|---|
| 3×3 9 square feet | 450w-600w | 1 to 4 |
| 2×4 8 square feet | 450w-600w | 1 to 4 |
| 4×4 16 square feet | 600w-1000w | 1 to 6 |
| 8×4 32 square feet | 600w-1600w | 1 to 8 |
400 Watt. 400-watt HPS bulbs provide about 44000 and 50000 lumens of light.
The parts of the plant exposed to the excess light will show physical symptoms. You might see the leaves droop before changes in color appear. Then pale or brown spots, or yellowing leaves can occur, even as the veins remain green and looking healthy.
The most apparent sign is leaf burning. This typically causes the yellowing of leaves at the top of the plant but the veins stay green, and the leaves take on a yellow or brown, burnt look.
Plants cannot get too much light, but they can get too much of the heat energy that comes with the light. Photosynthesis and other plant growth processes will shut down when the environmental and tissue temperature gets high enough that all the water taken up by the plant is used to cool the plant tissue.
1000-Watt HPS grow lights are the most powerful and cover a wider area of around 49 square feet.
What is too hot for a grow room?
If temperatures are above 85ºF during the flowering stage, the heat will stunt the bud growth. This can result in a loose and airy bud that lacks potency and smell. If left in high heat for too long, the plant may end up dying.
LED Grow lights are preferred because they consume less electricity than HPS lights. According to market research, LED lights consume 90 percent less power than HPS grow lights. You have less load on your amperage and electric breakers at home because LED grow lights enhance the energy efficiency of your indoor garden.
However, new and advanced LED lights not only offer equal light intensity; they also come with nuanced benefits that give growers more control than ever over their output. These days, you can count on LED lights to produce around 1-1.5 grams/watt, while the average yield for HPS grow lights is . 5 grams/watt.
First, the reddish output of HPS more closely resembles the natural sunlight a plant would absorb in the autumn seasons, which drives the plant's maximum flowering production. In addition, HPS lights provide higher light intensity (lumens) than MH.
Yield is roughly proportional to the amount of PAR light that a plant is given. Because of the lower PAR output per watt, the LED grow lights of the day produced less yield per watt of electricity than the benchmark HPS.
Whereas, the 600W HPS system's ideal hanging height is only 40cm (16"). Even at this low height, a lot of light will shine through the sidewalls and reflect onto the plant. The reflective materials will not capture all of the light, and some light will be lost (heating the walls).
Higher Yields
In one corner, we have a tried and tested workhorse, the 600w HPS light, capable of pumping out a respectable 150 to 300 grams in prime conditions. That's about 0.5 grams of cannabis per watt, a performance that has been the go-to choice for many growers.
The Sunmaster 600W Super Lumen HPS Lamp is a single-spectrum lamp with a very high 95,000 lumens output.
#1 LED lights are more efficient than HPS
And there's no way around it — LED is a much more energy-efficient solution, resulting in less utility cost over time to growers.
400W LED Grow Light Can Replace A 1000W HPS…
What LED wattage is equivalent to 600W HPS?
What LED Grow Light Is Equivalent to 600W HPS? A cultivator considering switching to LED should purchase a 200-watt panel to replace a 600-watt HPS grow light. LED panels produce 90,000 lumens just like the 600W HPS bulb while reducing electricity consumption by 50 percent.
Understanding grow lights
Lower K numbers are warmer more red coloured lights (good for stimulating flower growth), higher K numbers are cooler more blue coloured lights. For good foliage and root growth a cooler colour light with a kelvin rate of around 6500k is optimum.
' plants do require a daily respiration period of at least 6 hours per day (for seedlings) and ideally 8-10 hours for more mature plants. Therefore we do not recommend providing more than 14-16 hours per day of light, even if you are growing long-day-loving varieties and trying to induce flowering/fruit from them.
Leave the grow lights on for 14 to 16 hours per day to provide light for the young seedlings. It's best to turn the light on early in the morning and turn it off around dusk. Your seedlings will still thrive if you deviate from this schedule.
Green light is the least effective for plants because they are themselves green due to the pigment Chlorophyll. Different colored lights help plants achieve different goals. Blue light, for example, helps encourage vegetative leaf growth. Red light, when combined with blue, allows plants to flower.
So, why are your plants stretching? Well, when your plants stretch for light, this is called phototropism. This can be seen when your seedlings are left on a windowsill, the reason this is happening is because plants can detect wavelengths and light intensity at all angles.
And natural sunlight is in the range of 2,700 to 7,000 Kelvin. So, as a general rule of thumb, if you're looking to promote vegetative growth, pick lights ranging between 5,000 and 7,000 Kelvin. To promote fruiting and flowering, opt for lights in the 3,500 to 4,500 Kelvin range.
Pale green and yellow leaves that drop off are a sure sign of inadequate sunlight. Also, with variegated plants, the leaves will revert to a solid green color so the chlorophyll within can do its job. If your typically colorful plant has lost its color, move it to a sunnier place and see its color return.
A: In general, you should not leave grow lights on 24/7. Plants need a light-dark cycle to develop properly.
Lights that provide a full spectrum are the ideal choice for your growing space. This is where LED lights come in handy. Most LED growing lights offer both types of color spectrum lighting, so you can get all the benefits. TIP: Violet-blue light promotes plant growth and red light promotes plant budding.
How much does a 1000W HPS grow light cost per month?
| Watts | Hours Per Day | Cost Per Month |
|---|---|---|
| 100 | 8 | 6.08 |
| 200 | 8 | 12.17 |
| 400 | 8 | 24.34 |
| 1000 | 8 | 60.84 |
| Grow Room Size | Square Feet | Veg Wattage |
|---|---|---|
| 6' x 6' | 36 | 720 watts |
| 4' x 8' | 32 | 640 watts |
| 8' x 8' | 64 | 1,280 watts |
| 10' x 10' | 100 | 2,000 watts |
Yield Lab 1000W HPS Cool Hood Reflector Grow Light Kit (Price: $229.95) — With a 1000w grow light, you'll get 130,000 lumens from an HPS bulb and 110,000 lumens from an MH bulb. That's sufficient to provide coverage for up to 6 plants.
Cannabis growing experts will offer suggestions/solutions for keeping your grow rooms as close as possible to ideal conditions. The ideal temperature for growing cannabis indoors would be between 62°F to 72°F with lights off and between 68°F to 80°F with lights on.
Closed-loop systems involve having a completely sealed grow-room. No air is extracted out to or drawn in from outside the sealed grow-space. Instead, the temperature is kept within the right range by a heater and an air-conditioning unit. Humidity is controlled by the use of dehumidifiers and humidifiers.
Common grow room temperatures include (but are not limited to): Clones/Seedlings: 72-82°F. Vegging Stage: 68-78°F. Flowering Stage: 68-77°F.
As a general rule, 400w HPS bulbs are the most common, 600w HPS bulbs are the most efficient, and 1000w HPS bulbs are the most powerful (but also the hottest).
Commercial growers using HPS 1000W fixtures as their light source will typically need to 're-lamp' every 16 months or so. HPS lamps lose their intensity and die over time and should be changed after 10,000 hours of use.
The General Rule
For example, LED lights of 1000 watts are recommended to be placed 36 inches away from the plants. The lights can be lowered to 24 inches during the vegetative stage of the plant, and to 18 inches during the blooming or flowering stages.
Crop Type: Consider the light spectrum your crops require at different growth stages. LEDs offer customizable spectrums, while HPS lights are better suited for flowering plants. Energy Efficiency: LED lights are the eco-friendlier option, with their reduced energy consumption and heat output.
Can you mix LED and HPS lights?
In the case of an LED/HPS hybrid application, this combination of the two technologies can provide the ideal balance between diffuse light distribution and spectral efficiencies.
In many cases, using HPS grow lights requires additional ventilation for sufficient airflow. This can increase costs significantly. In addition, the high intensity light consumes a huge amount of energy, driving up costs while also causing more environmental damage.
Disadvantages: Poor Color - HPS bulbs have an orange glow which is difficult for the eye to see. HPS lit areas always seem to be appear dull and dim. Poor Lumen Maintenance - HPS bulbs will lose a considerable amount of light output before they completely burn out.
Typical lifespan values for an HPS bulb are around 24,000 hours. According to American Electric Lighting, “HPS lamps still generate 90% of their initial light output at the midpoint of their life span.
- Start with High Quality Seeds.
- Manipulate Plant Growth Direction.
- Increase Light Intensity.
- Automated Control of the Growing Environment.
- Automated Nutrient Supply.
- Pruning your Plants.
- Understanding the relationship between VPD and RH.
A 40W grow light that's on for the same number of hours will cost me 2.3 USD/month in electricity. The higher the wattage, the higher your electricity bill. All grow lights consume a certain amount of electricity. The amount of electricity they use is measured in watts (W).
The dangers of intense light
Leaf burn: If LED grow lights are placed too close to plants, the intense light can cause leaf burn. This is when the leaves become white or yellow and crisp, eventually dying off.
Each 600W grow light covers roughly a 1.2m x 1.2m area. That's enough space for 1 - 4 plants.
| # of Plants | Square Feet | Wattage from Wall |
|---|---|---|
| 4 | 4 | 160 watts |
| 6 | 6 | 240 watts |
| 8 | 8 | 320 watts |
| 10 | 10 | 400 watts |
The 400W HPS Grow Light Kit is designed to provide optimal coverage for an area of 80 x 80cm up to 1 x 1m. This makes it perfect for grow tents with 1 to 4 flowering plants.
How do I know if my grow light is too close?
Telltale Signs of Too Much Light
The most apparent sign is leaf burning. This typically causes the yellowing of leaves at the top of the plant but the veins stay green, and the leaves take on a yellow or brown, burnt look.
When you're just starting to foray into the world of larger grow lights, a 400W HPS is an appropriate first light to try. It's energy efficient, relatively cheap, and makes for large colas than stretch far down the plant.
According to our current data, the average wattage required per square foot is 32 watts (although this also depends on the plant, so we are taking averages here), so a 4×4 tent theoretically requires 512 watts for complete coverage. This number can float between 500 watts and 600 watts.
Plants require periods of both light and darkness to keep their metabolism and blooming phases in balance, and when they get too much light, those patterns are disrupted. While some plants need less darkness time than others, too much light will impede any growth schedule over time.
Under a 400W HPS light, you can fit 4–16 plants per m² in 5–12l containers.
For a 600W HPS Grow Light Kit, the gap should be: 150cm (small plants) 120cm (medium plants) 70cm (large plants)
| Watts | Hours Per Day | Cost Per Month |
|---|---|---|
| 100 | 8 | 6.08 |
| 200 | 8 | 12.17 |
| 400 | 8 | 24.34 |
| 1000 | 8 | 60.84 |
A: In general, you should not leave grow lights on 24/7. Plants need a light-dark cycle to develop properly.
In the vegetative stage, LED grow lights should be between 12-24 inches away from the top of the canopy. During this stage, more light is needed for photosynthesis, so the light source should be located closer to the plants. As the plants progress through the flowering stage, their demand for intense light decreases.
MH lamps provide a more natural appearance in color and are typically the choice for plants that have little to no natural light available. High Pressure Sodium (HPS) lamps provide more yellow/red spectrum, which is ideal for most plants that are actively fruiting and flowering.
